g factor measurements of μs isomeric states in neutron-rich nuclei around ⁶⁸Ni produced in projectile-fragmentation reactions

We report the first g factor measurement on microsecond isomers of neutronrich nuclei produced in projectile-fragmentation reactions at intermediate energies. The nuclides in the vicinity of ⁶⁸Ni were produced and spin oriented following the fragmentation of a ⁷⁶Ge, 61.4 MeV u^-1 beam at GANIL. The LISE spectrometer was used to select the nuclei of interest. The time-dependent perturbed angular distribution (TDPAD) method was applied in combination with the heavy-ion-gamma correlation technique to measure the g factors of ^69mCu (J^π = 13/2⁺, T_1/2 = 350 ns) and ^67mNi (J ^π = 9/2⁺, T_1/2 = 13.3 μs). Specific details of the experimental technique and the comparison of the results (|g(^69mCu)| = 0.225(25) and |g(^67mNi)| = 0.125(6)) with theoretical calculations are discussed. These results provide another indication of the importance of proton excitations across the Z = 28 shell gap.